1. Field of the Invention
The present invention is related to a double-phase half-wave brushless dc motor having two sensor/drive members. More particularly, the present invention is related to using two sensor/drive members to control a double-phase half-wave coil assembly of the brushless dc motor.
2. Description of the Related Art
Referring initially to FIG. 1, it illustrates a schematic circuitry of a conventional double-phase half-wave brushless dc motor. The double-phase half-wave brushless dc motor has a drive circuit 10 for driving a double-phase half-wave coil assembly. The drive circuit 10 includes a sensor/drive member 11 and two coils 12. The sensor/drive member 11 has two pins O1 and O2 for electrical connection, thereby connecting to the two coils 12. In function, the sensor/drive member 11 is applied to alternatively turning on or off for controlling the coil 12. Thereby, the sensor/drive member 11 is in control of conducting or cutting off the coil 12. Consequently, the two excited coils 12 are capable of rotating a motor rotor.
However, the rated power characteristic of the sensor/drive member 11 is changed nonlinear with respect to its dimensions. In other words, if the rated power of the sensor/drive member 11 is doubled, the dimensions have an increase of more than double. Thus, the increase of the rated power of the sensor/drive member 11 must result in an extra-occupation in an inner space of the motor.
Moreover, a large rated power of the sensor/drive member 11 must result in an increase of manufacturing cost. That is, the manufacturing cost of a double rated power of the sensor/drive member 11 must be more expensive than that of two regular rated power of the sensor/drive member 11.
In order to save the inner space and to reduce manufacturing cost of the motor, an additional sensor/drive member is added into the motor. Consequently, the motor accomplishes a double increase in rated power and a reduction in manufacturing cost.
The present invention intends to provide a double-phase half-wave brushless dc motor having two sensor/drive members for controlling a double-phase half-wave coil assembly, each of the sensor/drive members provided with a small rated power. Due to the small dimensions and the low manufacturing cost, the small rated power of the sensor/drive members substitute for a large rated power of the sensor/drive member that may enhance the rated power, minimize the dimensions and reduce the manufacturing cost. In manufacture, maximum number of the sensor/drive members of the motor is equal to or less than number of poles.
The primary objective of this invention is to provide a double-phase half-wave brushless dc motor having two sensor/drive members, each of which has small rated power adapted to control a double-phase half-wave coil assembly. Thereby, the two sensor/drive members may enhance the rated power of the double-phase half-wave brushless dc motor.
The secondary objective of this invention is to provide the double-phase half-wave brushless dc motor having two sensor/drive members, which have small dimensions and low manufacturing cost. Thereby, the two sensor/drive members may minimum the dimensions and lower the manufacturing cost of the double-phase half-wave brushless dc motor.
The double-phase half-wave brushless dc motor in accordance with the present invention includes a first sensor/drive member, a second sensor/drive member, a first motor coil and a second motor coil. Each of the sensor/drive members has two pins for electrical connection. Each of the motor coils is consisted of a first terminal and a second terminal for electrical connection. The first terminals of the first and second motor coils are commonly connected to a power source. The second terminal of the first motor coil is connected to one of the pins of the first sensor/drive member and one of the pins of the second sensor/drive member in common. And, the second terminal of the second motor coil is connected to the other pin of the first sensor/drive member and the other pin of the second sensor/drive member in common.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings.